When the blower fan is put in the low to middle position, it sounds like a bearing is bad in the motor or on the shaft. I do not here the souud when the fan is turned up to the highest position. This did not occur when new, however, over the past few months the noise seems to have increased.
What would cause the AC/Heater blower motor have a whining noise when running? on 2013 Ford F-250 Super Duty
by Jay Pfeiffer in Moncks Corner, SC on August 07, 2014
ANSWER by ProfessorG , August 07, 2014
Warranty? Or pull it and check it spinning it be hand, and check for looseness.